Sorry

Getting hacked on Twitter is fast becoming a rite of passage for big corporations, but Tuesday's attack on the Associated Press could be a tipping point and shows that social networks must do more to keep their users safe, security experts said.

Wider use of two-factor authentication, which can involve an access code being sent to a user on a second device such as a smartphone, is one possible solution. Such a mechanism could be introduced selectively, some experts said, for high profile accounts such as celebrities and large corporations.

"Twitter needs to get on board and make two-factor authentication available ... as fast as possible," said Andrew Storms, director of security operations at nCircle Security.

The AP's Twitter account was hacked Tuesday morning, resulting in a bogus tweet reporting that there were "two explosions in the White House and Barack Obama is injured." A group calling itself the Syrian Electronic Army claimed responsibility, via their own Twitter account.

The tweet was only visible for a matter of minutes, but the Dow Jones industrial average took a nose dive immediately after it was posted before recovering several minutes later. Unlike some previous hacking incidents, "this one had a real-world impact on the markets," noted Steve Brunetto , director of product management at EdgeWave, a social media and email security company.

The AP joins a list of companies that have recently been hacked on Twitter. Three CBS brands -- 60 Minutes, 48 Hours and a Denver news affiliate -- were hijacked this past weekend. The New York Times, The Wall Street Journal and The Washington Post have also been hacked in recent months. In February, Twitter announced the site itself had been breached.

The Twitter accounts of Burger King and the Jeep car company have also been compromised. After those incidents, Twitter urged users to be smarter with their passwords and in how they use the site.

Twitter has remained largely quiet following Tuesday's AP attack. "We don't comment on individual accounts for privacy and security reasons," a spokesman said. But now may be the perfect time for the social network to employ stronger safeguards to prevent future account breaches, some experts said.

Mark Risher, CEO at Impermium, an Internet security firm based in Redwood City, California, said he thinks Twitter already takes security seriously, but Tuesday's attack does "elevate" concerns, he said.

One strategy would be for Twitter to implement a two-step authentication system. In one common implementation, when users log into the site from their laptop, Twitter would send them a passcode to a second device, such as their mobile phone. They would then need to enter that code as well as their login and password to access the site.

Calls for Twitter to adopt such a system resurfaces whenever the site is hacked, but the AP attack could become a tipping point, said nCircle's Storms.

If Twitter doesn't want to mandate two-factor authentication for all accounts, the company could require it only for accounts that pass a certain number of followers, he suggested.

But accounts that employ two-step authentication may still be susceptible if those who use the accounts are subjected to an email phishing attack, said Impermium's Risher. "The hacker could fake a log-in page asking you for the code you just received," he said.

Alternatively, a phishing attack could be used to install a keystroke logger on a user's computer, recording their login and password the next time they enter it.

As an alternative, Twitter and other social networks should look more closely at how users interact with their services and watch for signals that might indicate unauthorized activity, said Risher, whose company develops algorithms to identify such activity. It might look at how users engage with content and how often they tweet and are retweeted, for example.

Twitter could also employ a risk-based authentication method, by asking users personal identification questions when they log in from an unfamiliar computer, for example.

Users could do more to safeguard their own social media accounts, however. Using stronger passwords, changing them frequently and protecting Wi-Fi networks with passwords are all recommended practices. Having a weak password may have played a role in the AP's account breach. The Syrian Electronic Army tweeted the alleged password "APm@rketing" later this afternoon.

But the onus should be on the social media sites to ensure the security of their users' accounts, Risher said. "It should be like an 80/20 split," he said, adding, "the lion's share of the work should be done by the sites."

Apple, Facebook and Google are among the companies that already offer two-step authentication as an option for users.

Twitter is a big target for breaches because of its immediacy, Obenhaim said. One of Twitter's primary purposes is to disseminate information in near real time, for example, while company pages on Facebook are often less active.

Other ideas that have been floated to keep accounts and identifies safe online include the use of "physical" passwords, which could take the form of a piece of jewelry. In a research paper released in January, Google said the current strategies, including the two-step verification system, are insufficient.

The stakes are high when it comes to cybersecurity, as Tuesday's stock market tumble showed. "Brand or character defamation is no longer the only outcome," said nCircle's Storms.

Posting fictitious tweets about outrageous behavior by employees at Burger King is one thing, but tweeting that the president has been injured following an explosion at the White House "can have a serious impact" more broadly, Duo's Oberheide noted.

Such hacks are also more significant since the U.S. Securities and Exchange Commission said it would allow public companies to disclose material corporate information on social media sites.

The SEC declined to comment Tuesday on the AP's and other recent Twitter hacks.